Re: simplify Arg[E^(I x)]?

*To*: mathgroup at smc.vnet.net*Subject*: [mg125771] Re: simplify Arg[E^(I x)]?*From*: David Reiss <dbreiss at gmail.com>*Date*: Sun, 1 Apr 2012 03:40:49 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jl6g1j$cm1$1@smc.vnet.net>

For a given value of x, Arg[Exp[I x]] is not necessarily equal to x: Plot[Arg[Exp[I x]], {x, 0, 4 Pi}] So, to get the answer you want, you need to restrict x as in: FullSimplify[Arg[E^(I x)], {x > -\[Pi], x <= \[Pi]}] --David On Mar 31, 4:42 am, Neal Becker <ndbeck... at gmail.com> wrote: > Why doesn't this simplify? > > Fullsimplify[Arg[E^(I x)], x \[Element] Reals] > > I expect to get 'x'. > > Is there some way I can get this to simplify?